packages: minor improvements for compiler packages (#50111)

Signed-off-by: Massimiliano Culpo <massimiliano.culpo@gmail.com>

etc/spack/defaults/darwin/packages.yaml

@@ -25,6 +25,8 @@ packages:
       glu: [apple-glu]
       unwind: [apple-libunwind]
       uuid: [apple-libuuid]
+  apple-clang:
+    buildable: false
   apple-gl:
     buildable: false
     externals:

etc/spack/defaults/packages.yaml

@@ -72,6 +72,8 @@ packages:
     permissions:
       read: world
       write: user
+  cce:
+    buildable: false
   cray-fftw:
     buildable: false
   cray-libsci:
@@ -86,6 +88,8 @@ packages:
     buildable: false
   essl:
     buildable: false
+  fj:
+    buildable: false
   fujitsu-mpi:
     buildable: false
   fujitsu-ssl2:
@@ -102,3 +106,5 @@ packages:
     buildable: false
   spectrum-mpi:
     buildable: false
+  xl:
+    buildable: false

etc/spack/defaults/windows/packages.yaml

@@ -23,3 +23,5 @@ packages:
   mpi:
     require:
     - one_of: [msmpi]
+  msvc:
+    buildable: false